In April 2020, the Environmental Protection Agency and the Army Corps of Engineers attempted to define the phrase through a regulation called the Navigable Waters Protection Rule (NWPR).
Colorado challenged the NWPR in federal court, arguing the new rule, despite its name, does very little to protect waters of the United States and is both substantively and procedurally flawed. Before the NWPR took effect, Colorado asked the district court to enjoin the Agencies from implementing the rule pending a determination on the merits of the case. The district court obliged; it issued an order staying the effective date of the NWPR and preliminarily enjoining the Agencies to continue administering the Clean Water Act under the then-current regulations.
Colorado Livestock Association along with Colorado Farm Bureau, Colorado Dairy Farmers, Colorado Pork Producers Council, Colorado Cattlemen’s Association, and Colorado Corn Growers Association filed an amicus brief in opposition to Colorado’s challenge of the Navigable Waters Protection Rule (NWPR).
The 10th Circuit reversed the district court, thereby reinstating the NWPR in Colorado because it found that Colorado failed to show it would be irreparably harmed by the NWPR.